> From: Greg Blevins [mailto:[EMAIL PROTECTED] > > Hello R experts, > > I have a data.frame which has a series of 30 variables that > are each coded 1,0--1 if a behavior is engaged in, 0 otherwise. > > The data.frame looks like this: > > var1 var2 ...var30 > Respondent 1 > Respondent 2 > etc > > I would like to create a matrix (or at least a half-matrix) > as follows: > > var1 var2 ...var30 > var1 > var 2 > . > . > var 30 > > where the number at each intersection is the number of people > who engaged in both behaviors. I could run a whole bunch of > tables and input the data by hand into a new matrix, but I > was wondering if there is a way to do this via a > program/function (I looked at "daisy," but concluded this > function would not handle this).
If I understood you correctly, the cross product of the matrix should do it. If your data frame is named "df", then you can do answer <- crossprod(data.matrix(df)) Hth, Andy > Any help would be appreciated! > > Greg Blevins > The Market Solutions Group > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo> /r-help > ------------------------------------------------------------------------------ Notice: This e-mail message, together with any attachments, ...{{dropped}} ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help